Portfolio assessment is one of the well-accepted authentic assessment types in early childhood education throughout the world. This study examines and compares the content of child portfolios from Turkiye and the United States (U.S.) to explore the factors providing assessment in child portfolios. To this end, a total of 19 child portfolios were analysed from a Reggio Emilia-inspired preschool and university preschool utilising a comparative approach. The findings unveiled the significance of common factors such as content, features of the selected products, reflections, and organisation, and these were elaborated on with examples in this paper.